Effector machine computation

ABSTRACT

An Effector machine is a new kind of computing machine. When implemented in hardware, the Effector machine can execute multiple instructions simultaneously because every one of its computing elements is active. This greatly enhances the computing speed. By executing a meta program whose instructions change the connections in a dynamic Effector machine, the Effector machine can perform tasks that digital computers are unable to compute.

I. FEDERALLY SPONSORED RESEARCH

Not Applicable.

II. COMPUTER PROGRAM IMPLEMENTING A STATIC EFFECTOR MACHINE

Attached with this patent application are two identical CD-ROMs. The following files are in directory static_effector_machine: SIZE DATE OF NAME (bytes) CREATION Machine.exe.txt 905,295 Mar. 16, 2003 ExecutionParameters.xml.txt 2,834 Mar. 17, 2003 MachineArchitecture.em.txt 1,402 Mar. 16, 2003 MachineArchitectureSize.em.txt 73 Dec. 16, 2002 MachineArchitectureTest.em.txt 1,045 Mar. 16, 2003 MachineInputProgram.em.txt 59 Mar. 16, 2003 MachineOutputProgram.em.txt 1,430 Mar. 16, 2003 mainMachineExecution.cpp.txt 1,717 Mar. 17, 2003

The file machine.exe is a software implementation of a static Effector machine. machine.exe is able to run properly in a Windows environment or an emulated Windows environment, assuming that the files, ExecutionParameter.xml, MachineArchitecture.em, MachineArchitectureProgram.em, MachineArchitectureSize.em, and MachineInputProgram.em, are in the same directory as machine.exe.

The file mainMachineExecution.cpp is source code that demonstrates how to program and execute the program on a static effector machine using the first method. In the function main of this file, the values of the machine architecture are read from the file MachineArchitecture.em and the static program is read from the file MachineInputProgram.em. The executable file machine.exe executes this static program on the machine architecture. After machine.exe executes, it stores the firing representation of the out-put effectors in the file MachineOutputProgrm.em.

As proof of concept, the executable file machine.exe demonstrates the execution of a static Effector machine on a digital computer. However, the Effector machine realizes far greater computational power when its machine instructions are directly implemented in suitable hardware. A good hardware implementation should enable the Effector machine to execute computations more than four orders of magnitude faster than today's digital computers.

III. BACKGROUND—FIELD OF INVENTION

The Effector machine is a new kind of asynchronous computer. The Effector machine is not a digital computer. Its design has been influenced by Alan Turing's work in mathematics and computer science and Wilfred Rall's research in neurophysiology.

IV. ADVANTAGES OF INVENTION OVER PRIOR ART

In a standard digital computer, the only active computing elements are specialized registers in the microprocessor. Usually only one machine instruction can be computed at a time. This creates a computational bottleneck. The Effector machine overcomes this bottleneck because every computing element is active. When implemented in hardware, the Effector machine can execute multiple machine instructions simultaneously. This enormously increases the computing speed over current digital computers.

An Effector machine can be implemented in hardware built from circuits of transistors that operate subthreshold. This reduces the amount of power consumed by more than 5 orders of magnitude. Further, the amount of heat produced is greatly reduced, compared to a digital computer.

Executing a meta program whose instructions change the connections in a dynamic Effector machine, enables the Effector machine to perform tasks that digital computers are unable to compute.

V. DETAILED DESCRIPTION OF INVENTION

1. Introduction

An Effector machine consists of computing elements called effectors. There are three kinds of effectors: Input, Computational and Output effectors. Input effectors receive information from the environment, another Effector machine, or a program. Computational effectors receive messages from the input effectors and other computational effectors firing activity and transmit new messages to computational and output effectors. The output effectors receive messages from the input and computational effectors firing activity. The firing activity of the output effectors represents the output of the Effector machine. Every effector is an ‘active element’ in the sense that each one can receive and transmit messages simultaneously.

This paragraph describes the fundamental method of computation of a static Effector machine. Each effector receives messages, formally called pulses, from other effectors and itself and transmits messages to other effectors and itself. If the messages received by effector, E_(i), at the same time sum to a value greater than the threshold, then effector E_(i) fires. When an effector E_(i) fires, it sends messages to other effectors. There are three kinds of effectors, computational, output and input effectors.

2. Machine Architecture

Definition 2.1 Static Machine The variables Γ, Λ, Δ represent index sets, used to index the input, computational, and output effectors, respectively. Depending on the particular machine architecture, it is possible for the intersections Γ ∩ Λ and Λ ∩ Δ to be empty or non-empty. A static machine

(

,

,

) consists of a collection of input effectors, denoted as

={E_(i): i ε Γ}; a collection of computational effectors

={E_(i): i ε Λ}; and a collection of output effectors

={E_(i): i ε Δ}. Each computational and output effector, E_(i), has the following elements:

-   -   A threshold θ_(i).     -   A refractory period r_(i), where r_(i)>0.     -   A collection of pulse amplitudes, {A_(ki)}_(kεΛ∪Λ).     -   A collection of pulse widths, {ω_(ki)}_(kεΓ∩Λ), where ω_(ki)>0         for all k ε Γ ∩ Λ.     -   A collection of transmission times, {τ_(ki)}_(kεΓ∪Λ), where         τ_(ki)>0 for all k ε Γ ∪ Λ.     -   A function of time, ψ_(i)(t), representing the time effector i         last fired. ψ_(i)(t)=supremum {s ε         : s<t AND g_(i)(s)=1}.     -   A set of recent firing times of Effector k within Effector i's         integrating window,         _(ki)(t)={s ε         : Effector k fired at time s and 0≦t−s−τ_(ki)<ω_(ki)}. Let |         _(ki)(t)| denote the number of elements in the set         _(ki)(t). If         _(ki)(t) is the empty set, then |         _(ki)(t)=0.     -   A collection of input functions, {φ_(ki)(t)}_(kεΓ∪Λ), each a         function of time, and representing pulses coming from         computational effectors, and input effectors. φ_(ki)(t)=|         _(ki)(t)|A_(ki).     -   An output function, g_(i)(t), representing whether the effector         fires at time t. ${g_{i}(t)} = \left\{ \begin{matrix}         1 & {if} & {{\sum\limits_{k \in {\Gamma\bigcup\Lambda}}{\phi_{ki}(t)}} > {\theta_{i}\quad{AND}\quad\left( {t - {\psi_{i}(t)}} \right)} \geq {r_{i}.}} \\         0 & {{otherwise}.} & \quad         \end{matrix} \right.$

An effector, E_(i), can be an input effector and a computational effector. Likewise, an effector can be an output effector and a computational effector.

As defined above, when an output effector, E_(i), is not a computational effector, i ε Δ ∩ {tilde over (Λ)}, E_(i) does not send pulses to effectors in this machine. This is captured formally by the fact that the index k for the transmission times, pulse widths, pulse amplitudes, and input functions lies in Γ ∩ Λ.

Input effectors that are not computational effectors have the same characteristics as computational effectors, except they have no input functions, φ_(ki)(t), coming from effectors in this machine. In other words, they don't receive pulses from effectors in this machine. Input effectors are assumed to be externally firable. An external source such as the environment or an output effector from another distinct machine

′(

′,

′,

′) can cause an input effector to fire. The input effector can fire at any time as long as this time minus the time the input effector last fired is greater than or equal to the input effector's refractory period.

Next, some vocabulary about the machine architecture is presented. If g_(i)(t₀)=1, this means effector i fired at time t₀. The refractory period, r_(i), is the amount of time that must elapse after effector E_(i) just fired before E_(i) can fire again. The transmission time, τ_(ki), is the amount of time it takes for effector E_(i) to find out that effector E_(k) has fired. The pulse amplitude, A_(ki), represents the strength of the pulse that effector k transmits to effector i after effector k has fired; after this pulse reaches E_(i), the pulse width ω_(ki) represents how long the pulse lasts as input to effector E_(i).

The expression connection from k to i represents the triplet (A_(ki), ω_(ki), τ_(ki)). If A_(ki)=0, then one says that there is no connection from effector k to effector i; if A_(ki)≠0, then one says there is a non-zero connection from effector k to effector i.

Definition 2.2 Dynamic Machine

A dynamic machine has the same definition as a static machine, except the connections, (A_(ki)(s),ω_(ki)(s),τ_(ki)(s)) change over time. Each of the connection variables is written as a function of s, which is a parameter for time. Thus, the pulse amplitudes, pulse widths and transmission times may change over time.

Stated in a more precise manner, replace the static machine definition of recent firing times with

_(ki)(t)={s ε

: Effector k fired at time s and 0≦t−s−τ_(ki)(s)<ω_(ki)(s)}.

Furthermore, replace the static machine definition of input functions with the definition ${{\phi_{ki}(t)} = {\sum\limits_{s \in {(t)}}^{\quad}\quad{A_{ki}(s)}}},$ where {φ_(ki)(t)}_(kεΓ∩Λ) is a collection of input functions.

3. Firing Representation of Effectors

Consider effector E_(i)'s firing times F(E_(i))={s: g_(i)(s)=1}. If E_(i)'s refractory period is greater than zero, arrange the elements of the set F(E_(i)) into a sequence [s₀, s₁, s₂, . . . ], where s₀<s₁<s₂< . . . .

Definition 3.1 Firing Representations

Consider the interval of time W=[t₁, t₂]. Let s_(m) be the smallest element lying in W, and s_(n) the largest element lying in W. Then E_(i)'s firing sequence within the window of computation W is F(E_(i), W)=[s_(m), s_(m+1), . . . , s_(n)], where s_(m)<s_(m+1)< . . . <s_(n−1)<s_(n), and ∪ {s_(k)}=s ε W: g_(i)(s)=1}. The sequence F(E_(i), W) is called a firing representation of the effector E_(i) over the interval of time W. With a collection of effectors {E₀, E₁, E₂, . . . }, create the infinite tuple (F(E₀, W),F(E₁, W),F(E₂, W), . . . ). The infinite tuple (F(E₀, W), F(E₁, W), F(F₂, W) . . . ) is called a firing representation of the effectors {E₀E₁, E₂, . . . } over the window of computation W.

At a fundamental level of interpretation, firing representations express the input to, the computation of, and the output of an Effector machine. At a more abstract level, firing representations can represent an input symbol, an output symbol, a sequence of symbols, a number, or even a sequence of program instructions.

EXAMPLE 3.2

For each real number x in [0,1], there exists a distinct firing representation of effectors {E₀, E₁, E₂, . . . } over a finite interval of time.

Proof: Let γ>0 be a finite real number. Choose the interval of time for each effector to be [0, γ]. For any time t<0, there are no restrictions on when effectors E_(i) fired. With this in mind, for each i choose the refractor period r_(i)=γ/2 so that it is possible for effector E_(i) to fire or to not fire during the interval of time [0, γ]. The sequence (b₀, b₁, b₂, b₃. . . ) is a binary representation of a real number x in [0, 1]. If b_(i)=1, then choose E_(i) to fire at least once during the interval of time [0, γ]. If b_(i)=0, then choose E_(i) to not fire during the interval of time [0, γ]. This shows the existence of a firing representation for x. To show distinctness, verify that if x≠γ, then the firing representation for x is distinct from the firing representation for y. Let (b₀, b₁, b₂, b₃, . . . ) denote the binary representation for x and (c₀, c₁, c₂, c₃, . . . ) denote the binary representation for y. Since x≠y, then c_(k)≠b_(k) for some k. In the first case, b_(k)=0 and c_(k)=1. (The analysis for the other case b_(k)=1 and c_(k)=0 is apparent from symmetry.) By our method of construction, the E_(k) effector for x does not fire during the interval of time [0, γ]; and the E_(k) effector for y fires during the interval of time [0, γ]. Thus, the firing representations for x and y are distinct. □

Definition 3.3 Sequence of Firing Representations

={E₀, E₁, E₂, . . . } denotes a collection of effectors. Let W₁, W₂, W₃, . . . , W_(n) be a sequence of time intervals. Let F(

, W₁)=(F(E₀, W₁), F(E₁, W₁), F(E₂, W₁), . . . ) be a firing representation over the interval W₁. Let F(

, W₂)=(F(E₀, W₂), F(E₁, W₂), F(E₂, W₂), . . . ) be a firing representation of the effectors {E₀, E₁, E₂, . . . } over the interval of time W₂. In general, let F(

, W_(i))=(F(E₀, W_(i)), F(E₁, W_(i)), F(E₂, W_(i)), . . . ) be the firing representation over the interval of time W_(i). From these one can create a sequence of firing representations, F(

, W₁), F(

, W₂), F(

, W₃), . . . , F(

, W_(n)).

4. Machine Computation

Definition 4.1 Machine Computation

Let F(

, W₁), F(

, W₂), F(

, W₃), . . . , F(

, W_(n)) denote a sequence of firing representations. Let F(

, S₁), F(

, S₂), F(

, S₃), . . . , F(

, S_(n)) be a sequence of firing representations. If there exists a machine architecture for an Effector machine whose input effectors with a sequence of firing representations F(

, S₁), F(

, S₂), F(

, S₃), . . . , F(

, S_(n)), generate with its output effectors F(

, W₁), F(

, W₂), F(

, W₃), . . . , F(

, W_(n)), then one says that the machine computes F(

, W₁), F(

, W₂), F(

, W₃), . . . , F(

, W_(n))

Definition 4.2

An Effector machine is an interpretation between two sequences of firing representations if the machine can compute the output sequence of firing representations from the input sequence of firing representations.

When using a dynamic machine, it is possible to use a distinct machine architecture for each distinct sequence of firing representations described in Definition 4.2.

Definition 4.3 Static Program

(

,

,

) denotes an Effector machine.

can be a static or dynamic machine. A static program is a sequence of firing representations presented to

(

,

,

)'s input effectors,

.

A meta-program determines how to change a dynamic machine's architecture as it executes.

Definition 4.4 Meta Program

(

,

,

) denotes a dynamic machine. For each j, the symbol x^(i) is the symbol A, ω or r, representing a pulse amplitude, a pulse width or a transmission time, respectively. A meta-program is a finite sequence of quintuples [(x¹, k₁, i₁, v₁, t₁), (x², k₂, i₂, v₂, t₂), . . . , (x^(n), k_(n), i_(n), v_(n), t_(n))] where each t_(i) represents a time and t₁<t₂< . . . <t_(n). For each j, where 1≦j≦n, the quintuple, (x^(j), k_(j), i_(j), v_(j), t_(j)), instructs

(

,

,

) to assign the value v_(j) to connection element, x^(j)k_(j)i_(j), at time t_(j). In particular, at time t₁, connection element, x¹k₁i₁, is assigned the value v₁. If x¹ is the symbol A, then pulse amplitude A_(k) ₁ _(i) ₁ is assigned the value v₁ at time t₁. Similarly, at time t₂, connection element, x² _(k) ₂ _(i) ₂ , is assigned the value v₂. If x² is the symbol ω, then pulse width ω_(k) ₂ _(i) ₂ is assigned the value v₂ at time t₂.

Example of Programming an Effector Machine

In the enclosed CD-rom, there is a file MachineInputProgram.em that contains an example of a Static program. The first line of this Static program has 0 in the time column and 0 in the effector column. The first line instructs that input effector 0 is fired at time 0. The second line has a 5 in the time column and a 0 in the effector column. This second line instructs that input effector 0 is fired at time 5. The last instruction is on the third line. The third line instructs that input effector 0 is fired at time 11. The simple static program in MachineInputProgram.em helps illustrate how a static program is interpreted by a static Effector machine. Longer more complex static programs can also be executed with machine.exe.

In the file MachineOutputProgram.em, the first line of this static program has a 3.00 in the time column and 0 in the effector column. The first line means that output effector 0 fired at time 3.00. The second line of this static program has a 4.00 in the time column and 0 in the effector column. The second line means that output effector 0 fired at time 4.00. The rest of the lines in file MachineOutputProgram.em are interpreted in a similar way.

The output file, MachineOutputProgram.em, has the same format as the input file, MachineInputProgram.em, so the output of one machine can be used as a static program for another machine. This enables one to compose the results of one or more Effector machines. Using machine composition, a programmer can program a complex task with many small Effector machines that perform simpler tasks.

5. Input and Output Interpreter

Two different methods of programming an Effector machine are defined here. In the first method, called explicit programming, someone explicitly designs a machine architecture, and writes a Static program or Meta program.

The design of a machine architecture and a program, using elicit programming, were explained in sections 2, 3, and 4. Despite the fact that machine instructions for an Effector machine are quite different from a digital computer's machine instructions, explicit programming is analogous to writing a computer program in assembly language, C, or some other programming language for a digital computer.

A second method, called implicit programming, designs the architecture and programs of an Effector machine based on how you want the machine to behave. A method for implicit programming is presented in the next section.

In both explicit programming and implicit programming, the use of an Input Interpreter and Output Interpreter greatly simplify the programming task. In any programming endeavor, the task that needs to be solved, performed or finished can be represented mathematically by an (input, output) set of pairs, {(I₁, O₁),(I₂, O₂), . . . }. In some cases, the set, {(I₁, O₁), (I₂, O₂), . . . (I_(n), O_(n))} is finite. In other cases, it can be infinite. For each i, I_(i) is the input point, and O_(i) is the corresponding output point. The (input, output) set specifies the behavior of the Effector machine that we wish to design.

An input and output interpreter translates a chosen pair (I_(i), O_(i)) to the native machine instructions of the Effector machine; specifically, the input interpreter translates the point I_(i), into a sequence of firing activity executed by the input effectors,

. The output interpreter translates the firing activity of the output effectors,

, into an output point, O_(i). This output point represents the output of the effector machine. On the attached CD-rom, the input interpreter and output interpreter are designed with C++ source code and can change, depending on what the Effector machine is designed to do. However, an input interpreter can be implemented as a distinct Effector machine. Likewise, an output interpreter can be implemented as a distinct Effector machine.

6. Evolutionary Design of an Effector Machine

Implicit programming on an Effector machine can be accomplished using evolutionary methods. Evolutionary methods for extremely different applications were first introduced by [Box], [Bledsoe], [Bremermann], and [Friedman].

Implicit programming is preferable to explicit programming when the programmer knows what she wants the Effector machine to accomplish, but she doesn't know how to explicitly design the Effector machine architecture, Static program or Meta program. This is analogous to a CEO of a company asking her engineers to build a new computer, but she does not know how to build this computer. The CEO knows how she wants the computer to behave, but does not know how to explicitly build it.

This paragraph introduces some definitions needed to present an evolutionary design process, called Cyclic Graph Evolution. The number of Effector machines in each generation of the evolutionary process is m, where m is an even number. The symbol p_(crossover) denotes the probability that two machines chosen for the next generation will be crossed over. The symbol p_(mutation) denotes the probability that a machine will be mutated. The symbol θ represents an optimal fitness value. In other words, if an Effector machine has a fitness value greater than θ, then it can competently compute the (input, output) set of pairs, {(I₁, O₁), (I₂, O₂), . . . }.

This paragraph presents the primary steps of Cyclic Graph Evolution, which will be abbreviated with the letters, CGE. CGE designs at least one effector machine that competently computes the collection of (input, output) pairs, {(I₁, O₁), (I₂, O₂), . . . , (I_(n), O_(n))}.

Build an initial generation of Effector machines, A={

₁,

₂,

₃, . . . ,

_(m)]. Determine the fitness of each Effector machine,

_(j). The fitness of

_(j) is determined by its overall ability to represent, O_(i), with its output effectors, after

_(j)'s input effectors receive input I_(i). The fitness is also dependent on the amount of memory

_(j) consumes and the average amount of computational time that it takes to compute the outputs O_(i). A smaller amount of memory increases the fitness. A smaller computational time increases the fitness also. During one generation, CGE randomly chooses two machines from the current generation based on their fitness. Sometimes these two machines selected are crossed over and mutated. After a possible crossover and mutation, these two machines are placed in the next generation. The selection of two machines, and possible crossover and mutation is repeated until the next generation has m machines. CGE is repeated until the best Effector machine

_(best) has a fitness greater than θ.

The CGE design process is presented below as an algorithm:

Cyclic Graph Evolution Designs Effector Machines

Build an initial population of machines, A={

₁,

₂,

₃, . . . ,

_(m)}. while(true) { Set G equal to the empty set. (G stores the machines in the next generation.) For each j in {1,2,3,...,M} { For each i in {1,2,3,...,n}, find M_(j)'s overall ability to represent, O_(i), with its output effectors, after M_(j)'s input effectors receive input I_(i). Store this ability as the fitness of M_(j). } Set q equal to the number of machines with fitness greater than 0. if (q ≧ 1) exit the loop while(true) and return M_(best), the machine with the highest fitness. while( the size of G < m) { Randomly choose two machines, M_(j), M_(k), from A for the next generation. (The probability of choosing M_(j), is proportional to its fitness.) Randomly choose a number r between 0 and 1. If r < p_(crossover), then crossover machines M_(j) and M_(k). Randomly choose numbers s₁, s₂ between 0 and 1. If s₁ < p_(mutation), then mutate machine M_(j). If s₂ < p_(mutation), then mutate machine M_(k). Set G equal to G∪{M_(j),M_(k)}. } Set A equal to G. }

Further Details on Cyclic Graph Evolution

A.) This part covers in further detail the construction of the effector machines in the initial population. Each machine is constructed separately. The stucture of how connections and effectors are organized in a machine must be explained first. Each machine that is designed by cyclic graph evolution is composed of one Input module, one Output module, and one or more Internal modules. (Refer to the diagram titled Effector Machine Structure used in Cyclic Graph Evolution.) Every effector lies in exactly one module. This structure does not affect how the Effector machine computes, as explained in Section 2, but it does affect how two machines are created for CGE, crossed over and mutated. A non-zero connection between two effectors lying in two distinct modules is called an external connection. A non-zero connection between two effectors lying in the same module is called an internal connection.

Please refer to the file EvolutionConstants.xml, stored on the CD-ROM, as we discuss the constants used in the construction of a machine. For each machine created, an Input Module and an Output Module are created. Further, a random number k is chosen such that MIN_MODULES_PER_MACHINE≦k≦MAX_MODULES_PER_MACHINE, and k internal modules are created.

Each module is constructed separately. External connections are added afterwards. For each module, a random u is chosen such that MIN_EFFECTORS_PER_MODULE≦u≦MAX_EFFECTORS_PER_MODULE.

Next, u effectors are created. For each effector, the refractory period is randomly chosen between MIN_REFRACTORY_PERIOD and MAX_REFRACTORY_PERIOD. For each effector, the threshold is randomly chosen between MIN_THRESHOLD and MAX_THRESHOLD. Next, for each effector, a random number v is chosen such that MIN_NUM_CONNECTIONS≦v≦MAX_NUM_CONNECTIONS. This means that v connections are created for this particular effector.

For each of these v connections, the value of the pulse amplitude is randomly chosen between MIN_AMPLITUDE and MAX_AMPLITUDE, inclusive. For each connection, the value of the pulse width is randomly chosen between MIN_PULSE_WIDTH and MAX_PULSE_WIDTH, inclusive. For each connection, the transmission time is randomly chosen between MIN_CONDUCTION_TIME and MAX_CONDUCTION_TIME, inclusive.

B.) This part explains how CGE executes a crossover between two machines, machine A and machine B. Please refer to the diagram titled, CGE Crossover. The variable n₁ represents the number of internal modules in the machine A, and n₂ represents the number of internal modules in machine B. For machine A, a random whole number j₁ is chosen, lying between LOWER_FRACTION_NUM_MODULES*n_(i) and UPPER_FRACTION_NUM_MODULES*n_(i). For machine B, a random whole number j₂ is chosen, lying between LOWER_FRACTION_NUM_MODULES*n₂ and UPPER_FRACTION_NUM_MODULES*n₂.

In the diagram, for machine A, j₁=2 was selected. For machine B, j₂=1 was selected. Since j₁=2, two distinct numbers are chosen randomly from the set {1, 2, . . . , n₁}. For machine A, these two numbers are 2 and 3. Since j₂=1, one number is randomly chosen from {1, 2, . . . , n₂}. In this case, 2 was chosen. What all this means is that internal modules m₂ and m₃ of Machine A are crossed over with internal module m₂ of Machine B. All the external connections to these modules are also severed. In the diagram, after crossover, new external connections are created and added to the internal modules that were crossed over. Observe that internal connections in a module that is crossed over are not changed or severed after crossover. This is why these objects are called modules. Internal connections are not severed by a crossover.

C.) This part further discusses mutations of an Effector Machine. There are multiple ways to mutate an Effector machine. An effector can be added to a module along with some non-zero connections, connecting the new effector to effectors inside the same module, and possibly connecting it to effectors in different modules. A second type of mutation deletes an effector. In this case, all of the deleted effector's non-zero connections are removed also.

A third type of mutation may change the pulse amplitude, pulse width, or the transmission time of a connection. Similar to adding an effector, a fourth type of mutation adds a new connection. Similar to removing an effector, a fifth type of mutation removes a connection from the Effector machine.

A sixth type of mutation creates a new module containing new effectors and connections between them and connects this new module to other modules with new external connections. A seventh type of mutation deletes a module and removes all of the deleted module's external connections.

The file EvolutionConstants.xml contains constants that guide these seven different types of mutations., In addition, implementations of these mutations in C⁺⁺ source code are in the directory evolution on the enclosed CD-ROM. Generally, p_(crossover) should usually range from 0.3 to 0.7. Also, p_(mutation) should usually be less than 0.1.

D.) Previous evolutionary methods evolve directed graphs that contain no cycles. Let V={v₁, v₂, . . . , v_(n)} be a finite set of n vertices. An edge in a directed graph is an ordered pair (v_(i), v_(j)) with each vertex lying in V. Let E={(v_(i) ₁ , v_(k) ₁ ), (v_(i) ₂ , v_(k) ₂ ), . . . , (v_(i) _(m) , v_(k) _(m) )} be a finite set of edges. A directed graph is formally,

=(V, E), where E and V have just been defined.

In a directed graph diagram, a dot represents a vertex. A line segment with one arrow pointing from one vertex to the other vertex represents a directed edge. The diagram titled, Directed Graphs shows one graph that contains a cycle and another that does not contain a cycle so it is called a tree.

A useful analogy is that the structure of hyperlinks on the World Wide Web is a directed graph because it is possible to click on a link to go to web page A, by clicking on a link while at web page B, but not vice versa. In mathematical language, (B, A) is an edge in the directed graph, but (A, B) is NOT an edge.

CGE is the first evolutionary method to evolve directed graphs containing cycles. It is also the first evolutionary method to crossover and mutate these directed graphs containing cycles.

E.) In previous evolutionary methods, each vertex represents a static function. The directed edge represents output from one function delivered as input to the other function. Because of this structure, information does not flow in the opposite direction. Furthermore in a function, the output can not be computed until it receives the input. Consequently, information flows in a synchronized way.

On the other hand, the objects that CGE operates on are entirely different. Effectors have more structure, more flexibility, and more computing capability than functions. Each vertex represents one effector, and each directed edge represents a non-zero connection from effector A to B. Furthermore, it is also possible to have a non-zero connection from effector B to A, so information flows asynchronously in both directions. Most importantly, effectors can change over time, so an effector can mimic the behavior of an infinite number of functions.

F.) CGE can also improve the design of analog VLSI circuits which are suitable for implementing Effector machines in hardware. One of Mead's primary methods of designing subthreshold analog circuits, [MEAD], is to use piecewise linear analysis to design non-linear circuits. Piecewise linear analysis becomes mathematically intractable as the size of the circuit increases. Also, piecewise linear analysis often requires a person to come up with clever techniques for predicting how the circuit will behave. In other words, it is very difficult to write a computer program that could automate the design of these circuits, using piecewise linear analysis. This greatly increases the time and financial cost of designing these circuits. CGE does not require cleverness. One can treat the analog VLSI circuit as a black box. All you need to know is for a set of inputs {I₁, I₂, . . . }, what set of corresponding outputs, {O₁, O₂. . . ,}, are required of the analog VLSI circuit. Then execute CGE on the (input, output) set, {(I₁, O₁), (I₂, O₂), (I₃, O₃), . . . }.

7. Hardware Implementation of Effectors

This section addresses the implementation of an Effector machine in hardware; an example is a semiconductor chip. In a hardware implementation of an Effector machine, computation still can be robustly executed even though there may be a small amount of variance in the transmission time or the exact time an effector is supposed to fire. The analysis below explains how to design an effector machine despite substantial variance in the physical parameters of the hardware.

Let r denote the refractory period of an effector. Let t_(detect) denote the time at which effector E_(i) detects some other effector fired. Let t_(actual) denote the actual time that this other effector fired. To make the analysis simpler to present, we ignore the transmission time from the effector that fired to the effector that received this firing information. Let ε_(i) denote the maximum possible value for |t_(detect)−t_(actual)|. Define ε=max{ε_(i): E_(i) is an effector in machine

}. If ε=0, then all effectors detect when another effector has fired with perfect precision. Let T denote a finite interval of time such that the hardware obeys 0≦ε<r<T. Refer to the diagram, titled Error Tolerance in Effectors.

Define χ: N×N→N as χ(L, n)=L*(L−2)*(L−4) . . . *(L−2n+2)=Π (L−2k+2). As an example, χ(7, 3)=7*5*3. As another example, χ(20, 5)=20*18*16*14*12. Choose T so that r divides T with zero remainder.

The formula: $\sum\limits_{n = 1}^{\frac{T}{r}}\quad\frac{{\chi\left( {\frac{T}{r},n} \right)}\left( \frac{r}{\varepsilon} \right)^{n}}{n!}$ is the maximum number of possible distinct firing configurations for an effector, during the interval of time T. This number of firing configurations determines the number of different states that the effector could be in during this time period.

The schematic diagram titled Effector Circuit illustrates how one Effector can be implemented with a circuit built from transistors that operate subthreshold. This technique reduces the amount of power consumed by more than 5 orders of magnitude. In Carver Mead's words, for a transistor to operate subthreshold means: “The gate voltage at which the mobile charge [in the transistor] begins to limit the flow of current is called the threshold voltage . . . . Most circuits described in this book operate in subthreshold—their gate voltages are well below the threshold voltage,” [MEAD]. Furthermore, when transistors operate subthreshold, the amount of heat produced is greatly reduced. 

1. A computing machine, comprising: (a) a collection of computing elements called Effectors, (b) a machine architecture that determines how the Effectors behave and determines how information is transmitted from one Effector to another Effector.
 2. The machine of claim 1 wherein a subset of said Effectors are configured to receive information from a Static program.
 3. (canceled)
 4. (canceled)
 5. A system comprising an input interpreter, the input interpreter being capable of at least partially designing at least the machine of claim
 1. 6. The machine of claim 5 wherein in said input interpreter is implemented with an Effector machine.
 7. (canceled)
 8. A system comprising the machine of claim 1 and an output interpreter, wherein the interpreter is capable of translating firing activity of a subset of said Effectors.
 9. The system of claim 8 wherein said output interpreter is implemented with an Effector machine.
 10. The machine of claim 1 wherein said machine is a dynamic machine.
 11. The machine of claim 10 wherein the machine is capable of running a Meta program that changes, over time, one or more properties associated with one or more of said Effectors.
 12. The machine of claim 1 wherein said machine architecture comprises hardware having a predetermined error tolerance.
 13. The machine of claim 12 wherein the hardware includes transistors configured to operate at subthreshold.
 14. A method comprising designing the machine of claim 1 at least partially by evolving a graph representing the machine.
 15. The method of claim 14 wherein the evolving of the graph includes at least performing a a crossover of two Effector machines via interchanging modules of Effectors.
 16. The method of claim 14 wherein said evolving the graph is capable of changing the following properties a number of modules per machine, a number of effectors per module, one or more refractory periods associated with one or more effectors, one or more thresholds associated with one or more effectors, a number of connections, one or more amplitudes associated with two or more effectors, one or more pulse widths associated with two or more effectors, and one or more conduction times associated with two or more effectors.
 17. A method, comprising: (a) providing a collection of computing elements called Effectors, (b) providing a machine architecture that determines how Effectors behave and determines how information is transmitted from one Effector to another Effector.
 18. The method of claim 17 wherein a subset of said Effectors, called Input Effectors, are capable of receiving information from an external environment.
 19. (canceled)
 20. (canceled)
 21. The method of claim 17 further comprising designing an Effector machine via an input interpreter.
 22. (canceled)
 23. The method of claim 17 further comprising designing said machine architecture by at least evolving a graph associated with the machine architecture.
 24. The method of claim 17, further comprising translating at least one firing activity of a subset of said Effectors, called Output Effectors.
 25. The method of claim 24 wherein the translating is performed via an output interpreter that is_implemented with an Effector machine.
 26. The method of claim 17 wherein the machine architecture and effectors are part of a dynamic machine.
 27. The method of claim 26, wherein the dynamic machine is capable of running a Meta program that changes, over time, one or more properties associated with one or more of the Effectors.
 28. The method of claim 17, further comprising designing said machine architecture based on an error tolerance.
 29. The method of claim 28 wherein said desiging includes at least configuring transistors to operate at subthreshold based on the error tolerance.
 30. (canceled)
 31. The method of claim 2 further comprising crossing over modules of Effectors between two Effector machines.
 32. The method of claim 2 wherein evolving the graph includes at least changing one or more of the following properties associated with at least a portion of the machine a number of modules per machine, a number of effectors per module, a refractory period associated with at least one of the Effectors, a threshold associated with an Effector, a number of connections between the Effectors, an amplitude associated with one or more of the Effectors, pulse width associated with one or more of the Effectors, and conduction time between at least two of the Effectors.
 33. (canceled)
 34. The method of claim 17 further comprising designing a least one circuit that is associated with the machine by at least evolving a graph associated with the circuit.
 35. The machine of claim 1 wherein a subset of said Effectors are configured to receive information from an external environment.
 36. The machine of claim 1 wherein a subset of said Effectors are configured to receive information from a distinct Effector machine.
 37. The machine of claim 1 wherein a subset of said Effectors are configured to receive information from a Meta program.
 38. The machine of claim 1 wherein a subset of said Effectors are capable of being configured to receive their information from an external environment; the subset of said Effectors are capable of being configured to receive information from a distinct Effector machine; the subset of said Effectors are capable of being configured to receive information from a Static program; the subset of said Effectors are capable of being configured to receive information from a Meta program; and the subset of said Effectors are capable of being configured to receive information from any combination of the external environment, distinct Effector machine, Static program, and the Meta program.
 39. The method of claim 14, wherein said evolving the graph includes at least changing a number of modules in the machine.
 40. The method of claim 14, wherein said evolving the graph includes at least changing a number of effectors per module.
 41. The method of claim 14, wherein said evolving the graph includes at least changing one or more refractory periods associated with one or more Effectors.
 42. The method of claim 14, wherein said evolving the graph includes at least changing one or more thresholds associated with one or more Effectors.
 43. The method of claim 14, wherein said evolving the graph includes at least changing a number of connections between two or more Effectors.
 44. The method of claim 14 wherein said evolving the graph includes at least changing one or more amplitudes associated with one or more Effectors.
 45. The method of claim 14 wherein said evolving the graph includes at least changing one or more pulse widths associated with the Effectors.
 46. The method of claim 14 wherein said evolving the graph includes at least changing one or more conduction times associated with the Effectors.
 47. A system comprising an input interpreter, the input interpreter being capable of at least partially designing at least a Static program for the machine of claim
 1. 48. A system comprising an input interpreter, the input interpreter being capable of at least partially designing at least a Meta program for the machine of claim
 1. 49. The machine of claim 10 wherein the machine is capable of running a Meta program that changes, over time, one or more properties of said machine.
 50. The method of claim 17 wherein a subset of said Effectors, called Input Effectors, are capable of receiving information from a distinct Effector machine.
 51. The method of claim 17 wherein a subset of said Effectors, called Input Effectors, are capable of receiving information from a Static program.
 52. The method of claim 17 wherein a subset of said Effectors, called Input Effectors, are capable of receiving information from a Meta program.
 53. The method of claim 17 wherein a subset of said Effectors, called Input Effectors, are capable of receiving information from an external environment; the Input Effectors are capable of receiving information from a distinct Effector machine; the Input Effectors are capable of receiving information from a Static program; and the Input Effectors are capable of receiving information from a Meta program.
 54. The method of claim 26 wherein the dynamic machine is capable of running a Meta program that changes, over time, a threshold associated with one or more Effectors.
 55. The method of claim 26 wherein the dynamic machine is capable of running a Meta program that changes, over time, a refractory period associated with one or more Effectors.
 56. The method of claim 26 wherein the dynamic machine is capable of running a Meta program that changes, over time, a pulse amplitude associated with two or more Effectors.
 57. The method of claim 26 wherein the dynamic machine is capable of running a Meta program that changes, over time, a pulse width associated with two or more Effectors.
 58. The method of claim 26 wherein the dynamic machine is capable of running a Meta program that changes, over time, a transmission time associated with two or more Effectors. 